1. Field of the Invention
The present invention relates to a thin-film transistor (“TFT”) substrate and a method of fabricating the same, and more particularly, to a TFT substrate which is structured to enhance performance and processing efficiency and a method of fabricating the TFT substrate.
2. Description of the Related Art
As modern society becomes more dependent on sophisticated information and communication technology, the market needs for larger and thinner display devices are growing. In particular, since conventional cathode ray tubes (“CRTs”) have failed to fully satisfy these market needs, the demand for flat panel displays (“FPDs”), such as plasma display panels (“PDPs”), plasma address liquid crystal display panels (“PALCs”), liquid crystal displays (“LCDs”), and organic light emitting diodes (“OLEDs”), is exploding.
A conventional display device includes a lower substrate which has an array of thin-film transistors (“TFTs”), an upper substrate which faces the lower substrate, and a liquid crystal layer which is interposed between the lower and upper substrates. The display device displays images by controlling the intensity of an electric field applied to the liquid crystal layer. The display device includes a gate driver and a data driver, which drive a display panel.
Since a plurality of TFTs are formed on the lower substrate, the lower substrate is also referred to as a TFT substrate. The TFT substrate is formed by patterning a plurality of thin-film patterns. Thin-film patterns are patterned by a photolithography process, which is accompanied by the processes of coating photoresist, mask alignment, exposure, baking, developing, and washing. To form the TFT substrate, the above processes may be combined in various ways.
In particular, if a semiconductor layer and data wiring are etched simultaneously by using a single mask, the semiconductor layer remains under the data wiring.
If the semiconductor layer remains under the data wiring, an aperture ratio may be reduced, or an afterimage may be formed as the semiconductor layer becomes conductive. Therefore, a TFT substrate, which is structured to enhance processing efficiency while removing a semiconductor layer under data wiring, and a method of fabricating the TFT substrate are required.